File System Mac Os X

FILE SYSTEM The file system in Mac OS X has at its core a set

of directories inherited from the Berkeley Software Distribution (BSD) operating system The Mac OS X file system was designed to provide power and flexibility while maintaining the traditional ease-of-use users expect the file system provides users with a consistent structure that makes it clear where resources are located

FILE SYSTEM  File System Domains 

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User - The user domain contains resources specific to the user who is logged in to the system - The user has complete control of what goes into this domain Local - The local domain contains resources such as applications and documents that are shared among all users of a particular system but are not needed for the system to run - Users with system administrator privileges can add, remove, and modify items in this domain Network - The network domain contains resources such as applications and documents that are shared among all users of a local area network - Items in this domain are typically located on network file servers and are under the control of a network administrator System - The system domain contains the system software installed by Apple - The resources in the system domain are required by the system to run - Users cannot add, remove, or alter items in this domain

FILE SYSTEM  Supported File Systems File System

Description

HFS

Mac OS Standard file system. Standard Macintosh file system for older versions of Mac OS.

HFS Plus

Mac OS Extended file system. Standard Macintosh file system for Mac OS X. Unix File System. A variant of the BSD “Fast File System.” Used for directly accessing files on the web. For example, iDisk uses WebDAV for accessing files.

UFS WebDAV UDF FAT SMB/CIFS AFP NFS FTP

Universal Disk Format. The standard file system for all forms of DVD media (video, ROM, RAM and RW) and some writable CD formats. The MS-DOS file system, with 16- and 32-bit variants. Used for sharing files with Microsoft Windows SMB file servers. AppleTalk Filing Protocol. The primary network file system for all versions of Mac OS. Network File System. A commonly-used BSD file sharing standard. Mac OS X supports NFSv2 and NFSv3 over TCP and UDP. A file system wrapper for the standard Internet File Transfer Protocol.

FILE SYSTEM  HFS+(Hierarchical File System Plus)  

the preferred file system on Mac OS X architecturally similar to HFS, with several important improvements such as: 

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32 bits used for allocation blocks (instead of 16). HFS divides the disk space on a partition into equal-sized allocation-blocks. Since 16 bits are used to refer to an allocation-block, there can be at most 216 allocation blocks on an HFS filesystem. Thus, using 32 bits for identifying allocation blocks results in much less wasted space (and more files). Long file names up to 255 characters Unicode based file name encoding File/Directory attributes can be extended in future (as opposed to being fixed size) In addition to a System Folder ID (for starting Apple operating systems), a dedicated startup file that can easily be found (its location and size are stored in the volume header in a fixed location) during startup, is also supported so that non-Apple systems can boot from a HFS+ file system Largest file size is 263 bytes HFS Plus uses B* tree to store most volume metada

FILE SYSTEM  UFS (Unix File System) 

a file system used by many Unix and Unix-like operating systems architecturally similar to HFS, with several important improvements such as: 

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a few blocks at the beginning of the partition reserved for boot blocks (which must be initialized separately from the file system) a superblock, containing a magic number identifying this as a UFS file system, and some other vital numbers describing this file system's geometry and statistics and behavioral tuning parameters a collection of cylinder groups

FILE SYSTEM  File System Comparisons Feature

HFS+

UFS

Case sensitive

No

Yes

Supports multiple file forks

Yes

No

Path separator character

“:”

“/”

Supports modification dates

Yes

Yes

Supports creation dates

Yes

No

Supports sparse files

No

Yes

Supports zero-filling of files

Yes

No

Supports aliases

Yes

No

Supports symbolic links

Yes

Yes

Supports ACLs

Yes

No

Supports creation dates

Yes

No